The Suffolk County treasurer has slammed a plan to merge her office with that of the county comptroller, saying the move is a “cynical” attempt to circumvent term limits for current comptroller Joseph Sawicki.

Angie Carpenter — a Republican who challenged County Executive Steve Bellone for that position in 2011 — said the plan approved by the county Legislature last month would not save the county money and would limit two offices’ ability to examine county finances.

“This is a cynical and calculated attempt to blend these two separate and distinct functions in an effort to diminish the necessary and prudent fiscal controls of Suffolk County and its $2.8 billion budget,” Ms. Carpenter said in a statement.

Supporters have said the proposed merger cuts away at inefficiencies in government.

“With our fiscal crisis, it is critical that we look at all opportunities where we can consolidate departments, improve efficiency and protect Suffolk County taxpayers,” Mr. Bellone (D-Babylon) said, adding that Suffolk is the only county in the state that has an elected treasurer and comptroller.

The Legislature approved the plan July 30 by a vote of 12-3, with two abstentions. County voters will decide the issue through a ballot referendum in November. The plan would combine the two offices and create a new administrative position called chief financial officer, which Mr. Sawicki would fill starting in January. He would be eligible to run for that position again in 2014. The Southold Republican is currently in his final term as comptroller.

Mr. Sawicki was out of the office this week and could not be reached for comment.